Commander Wolf Posted April 10, 2015 Posted April 10, 2015 (edited) Shortly after jtlan's CNJ1000, I set out to make a small PF boxcab of my own! I think like many of the earliest diesel electric locomotives in the US, the A6 had its beginnings in the Kaufman Act of the 1920s, which banned steam locomotives from operating in New York City. PRR built three A6 class two-axled switchers (3905-3907), one of which was repowered and reclassified A6B (3907), all of which operated in various New York yards between the late 1920s and late 1950s. Here is a picture of the lone A6B with some B1s up for scrap in 1961: This projext actually started out as one of those B1s, but along the way we found engineering drawings for the A6/B, and I was able to cram the drivetrain I'd designed for the B1 into the smaller body of the A6B. The unit is 24 studs long between couplers and has about 400 parts. The power comes from an AAA battery pack driving the old 9v geared motor. Not surprisingly the most difficult part of this model was figuring out how to position the battery pack, the geared motor, and that darn PF receiver inside the scaled dimensions of the loco. There weren't *that* many potential combinations of fit, but I had to go through a couple. In the end it's actually pretty tight given that the face of the receiver is already at the same height as the top of the curved slopes that make up the sides of the roof. The transmission is as simple as I could possibly make it: just 8-tooth gears meshed into 24-tooth crowns. You could actually speed this up by using 12 and 20 tooth bevels, but I prefer to go slower and have more pulling power - I want to be able to use the most worn out AAAs floating around and still go somewhere. Consequently the loco is *really* slow, but I'll call that a feature. Otherwise, the build is pretty straightforward, but I did try to make the top easily removable. My only real beef with this implementation is that the L drivers are slightly too big and the 1x1 tanks slightly too small. The receiption is also not amazing due to the positioning of the receiver, but it could be worse. There's a flap in the roof to access the power button. I have no idea what the big tank in the back is for. Someone enlighten me. More pics Bonus material #1: I tried my hand at "weathering" the unit by changing some of the brick colors, but I couldn't really get a combination with which I was happy: Bonus material #2: LDD of the B1 that I didn't finish. Pantographs are a pain. EDIT: Instructions now available for sale on Rebrickable: https://rebrickable.com/mocs/MOC-76470/NonsenseWars/148-pennsylvania-railroad-a6b-v2-powered-up/#details Edited January 5, 2022 by Commander Wolf Quote
dr_spock Posted April 10, 2015 Posted April 10, 2015 Great job. I love these little box cabs. Interesting to see how you used the 9V motor and how you would do a B1. I ended up with a BB1 in order to fit the M-motor, battery box and IR. Quote
zephyr1934 Posted April 10, 2015 Posted April 10, 2015 Oh wow, great little box cab. Unbelievable that you were able to fit all of the PF inside. Then on top of that such a good job detailing this little locomotive, excellent work! Quote
LEGO Train 12 Volts Posted April 10, 2015 Posted April 10, 2015 Commander you're the master of the impossible! This lovely locomotive powered with battery box and using the PF IR is unbelievable! I love the bogies and the contrast black and yellow! Great MOC! Quote
Commander Wolf Posted April 10, 2015 Author Posted April 10, 2015 Great job. I love these little box cabs. Interesting to see how you used the 9V motor and how you would do a B1. I ended up with a BB1 in order to fit the M-motor, battery box and IR. At my usual scale I was actually surprised at how big the B1 was - it has considerably more external volume. Unfortunately, the extra space is needed to do some of the details like the curved front, so the internal volume isn't actually much bigger than that of the A6. I liked my B1 body a bit more, but I think the A6 is a better overall implementation. Quote
Richfilth Posted April 10, 2015 Posted April 10, 2015 I think it's a great design, and I'm particularly pleased with the use of the old 9V motor - those torquey little lumps are great motors, and I wish Lego still made them. I need to source over a dozen for my final track setup. Quote
Asper Posted April 10, 2015 Posted April 10, 2015 Great design and interesting background story. Thank you for sharing. Quote
Commander Wolf Posted April 10, 2015 Author Posted April 10, 2015 I think it's a great design, and I'm particularly pleased with the use of the old 9V motor - those torquey little lumps are great motors, and I wish Lego still made them. I need to source over a dozen for my final track setup. I have to rant now: I really liked these old gear motors too, until I found out about the cracking magnets. I had seven of these old motors stored, untouched, in a cool and dry location, for several years and just a few weeks ago I discovered that four of the seven had seized up due to the cracking magnet! Between the nine motors, I have total, this is a failure rate of almost fifty percent, which is absurd. It also seems like they are impossible to dismantle without damaging the coil assembly, so it's impossible to change the cracked magnet even if you could find a replacement. Maybe the motors that have worked 'til now aren't subject to this issue, but it seems to me that just every one of these motors is a time bomb. Very, very disappointed by the poor quality of these units. Quote
cgarison Posted April 10, 2015 Posted April 10, 2015 Very nice build with lots of great detail. And fitting all that PF stuff into that little cab is wonderful. But do you have problems with the IR Receiver being partially blocked by the exhaust stack? Quote
Commander Wolf Posted April 12, 2015 Author Posted April 12, 2015 Very nice build with lots of great detail. And fitting all that PF stuff into that little cab is wonderful. But do you have problems with the IR Receiver being partially blocked by the exhaust stack? To be fair the reception is definitely not as good as some of my other PF models, but the alternative would have been to bury the receiver dome somewhere deep in the loco (ie have it accessible through a window, etc). At least compared to that option I think the current one is decent! Quote
pirzyk Posted April 12, 2015 Posted April 12, 2015 Ican't see the photo Brickshelf is down right now and I believe that is where the images are hosted :( Quote
Man with a hat Posted April 13, 2015 Posted April 13, 2015 Wow, what a great little train. Amazing details, especially the bogies. And eve more amazing it is PF. Quote
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